Lithium rich layered oxide xLi2MnO3∙(1−x)LiMO2 (M = Mn, Co, Ni, etc.) materials are promising cathode materials for next generation lithium ion batteries. However, the understanding of their electrochemical kinetic behaviors is limited. In this work, the phase separation behaviors and electrochemical kinetics of 0.5Li2MnO3∙0.5LiCoO2 materials with various Li2MnO3 domain sizes were studied. Despite having similar morphological, crystal and local atomic structures, materials with various Li2MnO3 domain sizes exhibited different phase separation behavior resulting in disparate lithium ion transport kinetics. For the first few cycles, the 0.5Li2MnO3∙0.5LiCoO2 material with a small Li2MnO3 domain size had higher lithium ion diffusion coefficients due to shorter diffusion path lengths. However, after extended cycles, the 0.5Li2MnO3∙0.5LiCoO2 material with larger Li2MnO3 domain size showed higher lithium ion diffusion coefficients, since the larger Li2MnO3 domain size could retard structural transitions. This leads to fewer structural rearrangements, reduced structural disorders and defects, which allows better lithium ion mobility in the material.

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Layered-layered composite oxides of the form xLi2MnO3·(1−x) LiMO2 (M = Mn, Co, Ni) have received much attention as candidate cathode materials for lithium ion batteries due to their high specific capacity (>250mAh/g) and wide operating voltage range of 2.0–4.8 V. However, the cathode materials of this class generally exhibit large capacity fade upon cycling and poor rate performance caused by structural transformations. Since electrochemical properties of the cathode materials are strongly dependent on their structural characteristics, the roles of these components in 0.5Li2MnO3·0.5LiCoO2 cathode material was the focus of this work. In this work, the influences of Li2MnO3 domain size and current rate on electrochemical properties of 0.5Li2MnO3·0.5LiCoO2 cathodes were studied. Experimental results obtained showed that a large domain size provided higher cycling stability. Furthermore, fast cycling rate was also found to help reduce possible structural changes from layered structure to spinel structure that takes place in continuous cycling.

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0.5Li2MnO3·0.5LiCoO2 composite cathodes prepared using various heating and cooling rates under 600 °C reveal different microstructural characteristics that significantly impact their structural stability and electrochemical properties.

Li-rich layered oxide (LLO) cathode materials, xLi2MnO3·(1-x)LiCoO2 (0<x<1, M= Mn, Ni, Co, etc.) are considered promising cathode materials in Li-ion batteries for large scale applications.

Lithium-rich layered oxide materials, xLi2MnO3·(1 − x)LiMO2 (M = Mn, Fe, Co, Ni, etc.), are a promising candidate for use as cathode materials in the batteries of electric vehicles (EVs).

Lithium metal orthosilicates, Li2MSiO4 (M = Fe, Mn, Co, Ni, and their mixtures), have been attracting significant attention as alternative cathodes for next‐generation high energy Li‐ion batteries (LIBs). The high capacity of these cathodes is attributed to two reversible transitions, those of Li2MSiO4 to LiMSiO4 and LiMSiO4 to MSiO4 phases involving two Li+ ions per mole. However, due to their complex structures and phase transformation behaviors, these materials are not yet available for practical commercial applications. Rate capability is one of the most important properties of cathode materials that are affected by phase transformations. This review will comprehensively summarize the current knowledge of the rate‐dependent phase transformations of Li2MSiO4 materials based on various characterization tools to facilitate future developments of these high potential cathode materials for future LIBs.